German Patent Application No. 10 2005 022 926 B3 shows a drive device with at least one electric engine, a manual transmission, and a differential. The electric engine includes a drive shaft which can rotate about a rotational drive axis. The drive shaft is effectively connected to a coaxial transmission shaft of the two-gear manual transmission in a torque-proof fashion. A drive sprocket is arranged on the drive shaft, which can be driven rotationally via the drive shaft about the axis of rotation of the electric engine. The drive sprocket engages with its teeth an interim wheel, which is located on an interim shaft.
The interim shaft carries two loose pulleys which, in reference to the interim shaft, can rotate about the axis of rotation of the interim shaft. A clutch is formed by a speed transformer, a slide collar, and coupling elements at the loose pulleys. An effective connection can be established by the electric engine engaging and disengaging optionally the dog clutch of one or the other loose pulley via a slide collar, which is linearly mobile along the axis of rotation of the interim shaft.
The mechanically operated mechanic speed transformer includes an input member in the form of a roll and an output member in the form of a shifting digit. The effective connection between the roll, rotational about its own axis of rotation, and the shifting digit is established by the peripherally circulating guide path, which deflects in the longitudinal direction and engages the shifting digit. When pivoting the roll about the axis of rotation of the roll the shifting digit travels along the guide path and is moved longitudinally according to the deflection of the guide path. This results in the slide collar with its dog clutch optionally engaging or disengaging a dog clutch of one of the loose pulleys. During the engagement, the loose pulley is fixed in its rotation to the interim shaft and accordingly it can rotate with the interim shaft about the axis of rotation of said interim shaft.
Each loose pulley engages with its teeth an input wheel of the differential, which is respectively fastened on the differential cage in a torque-proof fashion so that an effective connection is established between the manual transmission and the differential.
The differential is a classical bevel differential gear, by which the torque is distributed from the differential cage via compensation pinions to the differential side gears of a left and a right axial shaft. The axial shafts are connected with driven wheels of a vehicle; however they may also lead to driven axles when the differential is used in a transfer gearbox. The input wheels are concentric in reference to the central axes of the differential side gears.
The axial distances of the axis of rotation of the drive axles, axially parallel at a distance from the axis of rotation of the interim shaft and from the central axes depend on the transmissions of the gear speeds and the size of the torque to be transmitted. The construction space accordingly required for the drive device may be disadvantageously large.